1. Field of the Invention
The present invention relates to a vehicle control system that includes a battery mounted in a vehicle, an electrically operated device that is operated by electric power supplied from the battery and drives a critical system of the vehicle, electrically operated device control means for controlling the operation of the electrically operated device, and engine control means for controlling, by electric power supplied from the battery, the operation of an engine for making the vehicle travel.
2. Description of the Related Art
Japanese Patent Application Laid-open No. 11-5550 and Japanese Patent No. 3364673 disclose steer-by-wire (SBW) steering systems in which mechanical connection between a steering wheel and a steering gearbox is absent, and steering control means controls the drive of an electric motor provided in the steering gearbox based on an electrical signal generated by operation of the steering wheel, thereby turning left and right wheels.
However, because mechanical connection between the steering wheel and the steering gearbox is absent in the steer-by-wire steering system and the wheels are turned by driving the steering gearbox by the driving force of the electric motor which employs a battery as a power source, if the voltage of the battery that supplies electricity to the steering control means decreases, appropriate turning of the wheels may become impossible.